Is it allowed to drive MOSFET current in same dirn as diode

[xaccto]

Re: Is it allowed to drive MOSFET current in same dirn as di

Is it allowed to drive the MOSFET in the same direction as the integral diode?

let me explain,

firstly the normal scenario

should be no surprise there......

now

note the difference in current with mosfet ON 1.996AMP
and OFF 1.929AMP
hmm,
well spice can tell lies too but.....

can a mosfet be damaged like this ?

I'll not try this for real just yet

Added after 1 minutes:

reserve for part II

blah blah blah blah

 

[umesh49]

Even if there is no integral diode, FET can allow to flow the current in reverse direction (With gate is ON); I will check for some reference.
If you want the current to flow via diode (Gate is OFF) then you should look at data sheet. This diode used to have lower current capabillity than FET.

UMESH.

 

[FvM]

Re: Is it allowed to drive MOSFET current in same dirn as di

As a popular example, reverse drain current mode is the standard operation in the low-side switch of a synchronous buck converter.
Also H-briges are utilizing both drain current polarities. Reverse operation is usually not represented in the datasheet with explicite
characteristics. Because Vds is restricted to values below a diode forward voltage, you're effectively unable to see deviations from
linear Rdson behaviour. In other words, you can roughly apply the Rdson(Vgs) characteristic for inverse drain current as well.

 

[sec]

Re: Is it allowed to drive MOSFET current in same dirn as di

at lower current FET are used to simulate tube sound, well a clipped tube.

 

[xaccto]

Re: Is it allowed to drive MOSFET current in same dirn as di

thanks fvm, thats where I was heading